KSC2786YBU RF Transistor NPN Equivalent & Substitute Parts

Part Overview

The KSC2786YBU is an RF transistor NPN manufactured by onsemi, designed for RF applications requiring operation at 20V with a transition frequency of 600MHz. This through-hole TO-92S packaged device delivers 250mW maximum power dissipation and is classified as obsolete. Due to its obsolete status, equivalent and substitute parts from active manufacturers are necessary for new designs, production continuity, and long-term component availability. Substitute parts listed below maintain core RF transistor functionality while offering varying performance characteristics suited to different application requirements.

Substiute Parts

KSC2786YBU

onsemiIn Stock: 1170KSC2786YBU Datasheet

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BFP182RE7764HTSA1

Infineon TechnologiesIn Stock: 731BFP182RE7764HTSA1 Datasheet

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BFP640H6327XTSA1

Infineon TechnologiesIn Stock: 32002BFP640H6327XTSA1 Datasheet

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BFP840ESDH6327XTSA1

Infineon TechnologiesIn Stock: 1737BFP840ESDH6327XTSA1 Datasheet

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MAPRST0912-350

MACOM Technology SolutionsIn Stock: 823MAPRST0912-350 Datasheet

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MAX2601ESA+T

Analog Devices Inc./Maxim IntegratedIn Stock: 944MAX2601ESA+T Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the KSC2786YBU is determined by the following critical parameters: transistor type (NPN), voltage rating, frequency capability, power dissipation, and collector current capacity. The substitute parts listed below are grouped based on their ability to meet or exceed the electrical specifications of the original part while accommodating different mounting technologies and package formats.

Key Parameters for Substitution Assessment:

• Transistor Type: NPN (mandatory match)
• Voltage - Collector Emitter Breakdown (Max): ≥ 20V or application-specific lower ratings
• Frequency - Transition: ≥ 600MHz capability
• Power - Max: ≥ 250mW or application-specific lower ratings
• Current - Collector (Ic) (Max): ≥ 20mA or application-specific lower ratings
• Mounting Type: Through Hole or Surface Mount (design-dependent)
• Product Status: Active preferred for long-term availability

Substitute parts are presented across multiple manufacturers (Infineon Technologies, MACOM Technology Solutions, Analog Devices Inc./Maxim Integrated) with varying performance tiers to accommodate different application scenarios, from low-power RF circuits to high-power RF amplification stages.

Parameter Comparison

Engineering Selection Recommendations

BFP182RE7764HTSA1 (Infineon Technologies) This substitute maintains the 250mW power rating and provides enhanced frequency capability at 8GHz with improved noise figure performance. The 12V voltage rating accommodates applications requiring lower voltage operation. Product status is active with ROHS3 compliance. Surface mount packaging requires PCB design modification from the original through-hole configuration. Suitable for applications where frequency performance and compliance certifications are prioritized.

BFP640H6327XTSA1 (Infineon Technologies) This ultra-high-frequency device operates at 40GHz with superior noise characteristics and active product status. The 4.5V voltage rating restricts application to low-voltage RF circuits. The 200mW power rating is slightly reduced from the original specification. Surface mount SOT-343 packaging requires design adaptation. ROHS3 compliance and unlimited MSL rating ensure regulatory alignment. Appropriate for millimeter-wave and high-frequency RF applications.

BFP840ESDH6327XTSA1 (Infineon Technologies) Operating at 80GHz, this device represents the highest frequency capability among substitutes with active product status and ROHS3 compliance. The 2.25V voltage rating and 75mW power dissipation are significantly reduced, limiting application scope to ultra-low-power, high-frequency circuits. Surface mount SOT-343 packaging requires PCB redesign. Suitable for specialized high-frequency RF applications where voltage and power constraints are acceptable.

MAPRST0912-350 (MACOM Technology Solutions) This high-power substitute delivers 350W maximum power dissipation with 65V voltage rating, enabling RF power amplification applications far exceeding the original device capability. The 1.215GHz frequency rating exceeds the original 600MHz specification. Chassis mount configuration requires mechanical redesign. ROHS3 compliance and 200°C operating temperature provide extended thermal performance. Appropriate for high-power RF transmitter and amplifier stages.

MAX2601ESA+T (Analog Devices Inc./Maxim Integrated) This integrated RF transistor operates at 1GHz with 6.4W power dissipation and 1.2A collector current, providing significant performance enhancement over the original device. The 15V voltage rating closely matches the original 20V specification. Surface mount 8-SOIC-EP packaging requires PCB layout modification. ROHS3 compliance and active product status ensure regulatory and supply chain continuity. Suitable for general-purpose RF amplification and signal processing applications requiring higher power and current capacity.

Frequently Asked Questions (FAQ)

Q: Can the KSC2786YBU be directly replaced with any of these substitute parts without circuit modification?

A: Direct replacement without modification is not possible due to package format differences. The original KSC2786YBU uses through-hole TO-92S packaging, while all listed substitutes employ surface mount or chassis mount configurations. PCB layout and component placement must be redesigned accordingly. Additionally, electrical parameter variations require circuit impedance matching and biasing network adjustments.

Q: Which substitute part most closely matches the original KSC2786YBU specifications?

A: The BFP182RE7764HTSA1 maintains the 250mW power rating and provides comparable gain characteristics (22dB). However, it operates at 12V rather than 20V and requires surface mount implementation. The MAX2601ESA+T offers the closest voltage rating match at 15V with significantly enhanced power handling (6.4W) and active product status, though it requires surface mount packaging.

Q: What are the key differences between the Infineon BFP-series substitutes?

A: The three Infineon substitutes represent a frequency and power trade-off spectrum. The BFP182RE7764HTSA1 operates at 8GHz with 250mW power, suitable for microwave applications. The BFP640H6327XTSA1 reaches 40GHz with 200mW power for millimeter-wave circuits. The BFP840ESDH6327XTSA1 extends to 80GHz with reduced 75mW power for ultra-high-frequency applications. Voltage ratings decrease progressively across this series (12V, 4.5V, 2.25V), reflecting their specialized frequency domains.

Q: Is the MAPRST0912-350 suitable for direct replacement in low-power RF circuits?

A: No. The MAPRST0912-350 is designed for high-power RF amplification with 350W power dissipation and 32.5A collector current. Its specifications far exceed the original device requirements and would be inappropriate for low-power circuits. This substitute is intended for RF transmitter and power amplifier applications requiring substantially higher power handling than the original 250mW device.

Q: What packaging considerations must be addressed when substituting the KSC2786YBU?

A: The original through-hole TO-92S package requires conversion to surface mount (SOT-143R, SOT-343, 8-SOIC) or chassis mount formats. This necessitates complete PCB redesign, including trace routing, component placement, thermal management, and impedance matching networks. Surface mount substitutes require appropriate solder reflow processes and may demand different thermal management strategies compared to through-hole implementation.

Q: Are all substitute parts RoHS3 compliant?

A: All listed substitute parts carry ROHS3 compliance certification. The original KSC2786YBU does not specify RoHS status. This compliance ensures compatibility with modern manufacturing standards and regulatory requirements in electronics assembly and distribution.

Q: What is the significance of the noise figure specifications across these substitutes?

A: Noise figure indicates RF signal degradation introduced by the transistor. Lower values indicate superior performance. The original KSC2786YBU exhibits 3dB-5dB noise figure at 100MHz. Substitutes demonstrate improved noise performance at higher frequencies: BFP182RE7764HTSA1 (0.9dB-1.3dB @ 900MHz-1.8GHz), BFP640H6327XTSA1 (0.65dB-1.2dB @ 1.8GHz-6GHz), and BFP840ESDH6327XTSA1 (0.85dB @ 5.5GHz). Selection depends on operating frequency and noise budget requirements.

Q: How do voltage ratings affect substitute part selection?

A: Voltage rating determines maximum safe collector-emitter potential. The original 20V rating accommodates applications up to that voltage level. Substitutes with lower ratings (BFP640H6327XTSA1 at 4.5V, BFP840ESDH6327XTSA1 at 2.25V) restrict application to lower-voltage circuits. The MAPRST0912-350 at 65V and MAX2601ESA+T at 15V accommodate higher and comparable voltage requirements respectively. Circuit supply voltage must not exceed the selected substitute's voltage rating.

Q: What inventory considerations apply to these substitute parts?

A: All substitute parts maintain active product status with current inventory availability. The original KSC2786YBU is obsolete with limited remaining stock (1132 pcs). Substitutes offer long-term supply continuity: BFP182RE7764HTSA1 (696 pcs), BFP640H6327XTSA1 (31947 pcs), BFP840ESDH6327XTSA1 (1725 pcs), MAPRST0912-350 (748 pcs), and MAX2601ESA+T (925 pcs). Active product status ensures ongoing availability for production and design requirements.